Converting lower value renewable biomass, e.g., forestry and agricultural wastes, and disused polymers such as polyphenylene oxide (PPO) into higher value-added chemical products is becoming increasingly important for social, economic, and resource sustainability. Lignin is a major renewable biomass waste product in the pulp and paper industry, with a production of 150-180 million tons per year. On the other hand, polyphenylene oxide (PPO) is widely used as important engineering-plastics. Diaryl ether, a common 4-O-5 linkage lignin model compound and the building block of PPO, has the highest bond dissociation energy among the three types of ether linkages (including α-O-4, β-O-4 and 4-O-5) in lignins, and is the most challenging to cleave. Thus far, success has been achieved to cleave this type of ether bond to form simple molecules, including hydrocarbon (benzene, cyclohexane) and oxygen-containing compounds (phenol, cyclohexanol, cyclohexanone, and cyclohexylalkyl ether).
Converting cheap inorganic chemicals into high value-added organic chemicals has very important economic value.
There is thus still a need to be provided with means to convert lower value renewable biomass into high value-added organic chemicals.